Cycloalkanes – Classification, Structure, Examples and Properties

Organic Compounds And Cycloalkanes

Organic compounds are those that contain carbon and hydrogen atoms. Cycloalkanes are organic compounds that have a ring-shaped molecule.

Classification of Hydrocarbons

There are three classifications of hydrocarbons: alkanes, alkenes, and alkynes. Alkanes are saturated hydrocarbons that contain only single bonds between carbon atoms. Alkenes are unsaturated hydrocarbons that contain at least one double bond between carbon atoms. Alkynes are unsaturated hydrocarbons that contain at least one triple bond between carbon atoms.

Structure of Cycloalkanes

A cycloalkane is an alkane that has a ring of carbon atoms. The simplest cycloalkane is cyclopropane. Cycloalkanes have different physical and chemical properties than straight-chain alkanes because of their ring structure.

Cycloalkanes Examples

• Cycloalkanes are simple hydrocarbons that contain only carbon and hydrogen atoms. The simplest cycloalkane is cyclopropane, which has the formula C3H6. Cycloalkanes are named by replacing the -ane ending of the alkane name with -cyclo-. Cyclopropane is named cyclopropane, cyclobutane is named cyclobutane, and so on.
• Cycloalkanes have the property of being able to rotate about their carbon-carbon bonds. This is because the carbon-carbon bonds are not constrained by the presence of other atoms like oxygen or nitrogen. This rotation is what gives cycloalkanes their unique shape.

Nomenclature of Cycloalkanes

• The IUPAC system for naming cycloalkanes is to give the parent alkane the prefix cyclo-, followed by the number of carbon atoms in the ring. For example, the cycloalkane with six carbon atoms is called cyclohexane.
• If there is a branch on the ring, the branch gets the prefix iso-. For example, the cycloalkane with six carbon atoms and one branch is called isohexane.
• If there are two branches on the ring, the branches get the prefix di-. For example, the cycloalkane with six carbon atoms and two branches is called dihexane.
• If there are three branches on the ring, the branches get the prefix tri-. For example, the cycloalkane with six carbon atoms and three branches is called trihexane.
• If there are four branches on the ring, the branches get the prefix tetra-. For example, the cycloalkane with six carbon atoms and four branches is called tetrahexane.
• If there are five branches on the ring, the branches get the prefix penta-. For example, the cycloalkane with six carbon atoms and five branches is called pentahexane.

Cycloalkane Properties

The boiling point of a cycloalkane is higher than the corresponding alkane. This is because the cycloalkane has more ring strain.